Two editors makes no sense and I've frequently seen it lead to literal edit wars and drama (the sort of person who wants to be a fansub editor is often completely unable to admit that they are wrong or that someone else has a better idea). If your first editor isn't good enough to make the script make sense by himself, why did you recruit him in the first place? Sure, he might want to ask the opinion of someone else in some tricky spots, and/or you might want to have a second set of eyes checking for typos and copy editing errors, but two full-time editors work on the same show is dumb and a waste of resources.

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